Compression straps at a glance
- Where
- Sides of the pack body
- Job
- Take up empty volume so the load cannot shift
- Set them
- After packing, before you walk
What do compression straps actually do?
They make the pack smaller than its full volume. The Washington Trails Association describes them as straps on the sides of the pack that let you make the load more compact vertically, horizontally or both. A pack that is only partly full has empty space in it, and empty space is where a load slumps, slides and swings.
Cinching them pulls that slack out. The Appalachian Mountain Club's packing advice is to use them once everything is inside, to shrink the pack and stabilize the load, and REI's is the same: tighten them to streamline the load and keep it from shifting as you hike.
Why do they matter more on a half-full pack?
Because a load that can move will. On uneven ground a shifting load pulls you sideways just as your footing is least sure, and a loose pack sags away from your back. Compression straps are what let one pack carry a big load on one trip and a small one on the next without feeling wrong on either.
That is also why day hikers who size up for winter layers and traction are pointed at them. A bigger pack spends most of a winter day half empty, and compression is what keeps it riding tight.
Can you carry gear on compression straps?
Often, yes. REI lists compression straps alongside daisy chains and lash patches as a way to carry gear that will not fit anywhere else, such as trekking poles, tent poles or a large sleeping pad. Slide the item under the strap and cinch it down.
REI's caveat is worth taking seriously: anything on the outside can snag on branches or scrape against rock, so carry as little out there as you can. A foam pad strapped to the side of a pack is fine on an open trail and a nuisance in dense brush.
What this means when you're choosing
- More than one strap per side if your loads vary a lot from trip to trip
- Buckles that open, so a strap can go around a pad or a pair of poles
- Straps that still cinch with the extension collar rolled down, when the pack is at its smallest
- Whether a strap crosses a side pocket, which can pin a bottle in place or block your reach to it
Compression straps vs Load lifters
| Compression straps | Load lifters | |
|---|---|---|
| Where they are | On the sides of the pack body | From the top of the shoulder straps to the top of the frame |
| What they pull in | The pack body, around its contents | The top of the pack, toward your shoulders |
| Main job | Stop the load shifting inside the pack | Stop the pack leaning away from your back |
| When you set them | After packing, before you put the pack on | After the hipbelt and shoulder straps, with the pack on |
Which to pick: Most framed packs have both, because they solve different problems: compression straps steady what is inside the pack, and load lifters steady the pack against you.
The common mistake
Leaving them loose because the pack is not full
A half-full pack is exactly when they matter. The empty space lets the load slump to the bottom and slide side to side, and the pack sags away from your back. Pull them snug every time you finish packing, and loosen them only when you need to fit more in.
Common questions
Should compression straps be tight or loose?
Snug around the load once you have finished packing. Tight enough that nothing shifts when you shake the pack, and not so tight that hard items end up pressing into your back through the backpanel.
Are compression straps the same as load lifters?
No. Compression straps cinch the pack body in around its contents. Load lifters run from the top of the shoulder straps to the top of the frame and pull the whole pack in toward your shoulders.
Where this is defined
- How to Choose a Backpack, Washington Trails Association
- How to Pack a Backpack, Appalachian Mountain Club
- How to Pack a Backpack for Backpacking & Hiking, REI Co-op
See it labeled